For me, the issue was that OOP in an academic context was always toy examples. OK, Dog and Cat are Animal that can MakeNoise, Eat, and HaveFur (except sometimes

For me, the issue was that OOP in an academic context was always toy examples. OK, Dog and Cat are Animal that can MakeNoise, Eat, and HaveFur (except sometimes not). Yeah, I get it. It's a ridiculous amount of boilerplate compared to just throwing some functions in and getting it done. The issue was that anything they taught had to be dumbed down to the point to fit in a classroom and they basically stopped there. We also never wrote code that would be looked at by more than one person. I didn't "get it" until I spent years in a real job, with systems complex enough for this to matter, and practical examples like Dependency Inversion etc as you say. There was also a complete lack of Composition and (at the time I did it) multiple-inheritance which is a bit more controversial these days. Our traditional Comp Sci course also worked on a variety of languages but nearly zero UI or web programming back then, which are both natural fits for OOP that we largely ignored.